diff --git a/src/main/java/org/gcube/portlets/user/workspace/client/view/windows/DialogEditProperties.java b/src/main/java/org/gcube/portlets/user/workspace/client/view/windows/DialogEditProperties.java
index f2fef3c..5c67ecc 100644
--- a/src/main/java/org/gcube/portlets/user/workspace/client/view/windows/DialogEditProperties.java
+++ b/src/main/java/org/gcube/portlets/user/workspace/client/view/windows/DialogEditProperties.java
@@ -97,7 +97,8 @@ public class DialogEditProperties extends Dialog{
 	private void saveProperties(final boolean closeOnSuccess){
 		Map<String,String> prp = new HashMap<String, String>(fields.size());
 		for (TextField<String> field : fields) {
-			prp.put(field.getFieldLabel(), field.getValue());
+			String value = field.getValue()!=null?field.getValue():"";
+			prp.put(field.getFieldLabel(), value);
 		}
 		AppControllerExplorer.rpcWorkspaceService.setGcubeItemProperties(item.getIdentifier(), prp, new AsyncCallback<Void>() {